dyndbg's dynamic prefixing can get expensive; each enabled callsite's
prefix is sprintf'd into stack-mem, every time a pr_debug is called.
A cache would help, if callsites mark _DPRINTK_FLAGS_PREFIX_CACHED
after saving the prefix string. But not just yet.
_DPRINTK_FLAGS_INCL_LOOKUP distinguishes from _DPRINTK_FLAGS_INCL_ANY
by selecting *only* module,file,function fields to compose the
cacheable part of the (+tmfsl) dynamic prefix:
-t thread-id. not part of the "callsite" info, its from current.
doesn't belong in the cache. it would spoil it.
do it in outer: dynamic_emit_prefix()
-mfs module, function, source-file
they are "lookups", currently to struct _ddebug fields.
could be accessor macros to "compressed" tables.
then they might be worth caching, ready for reuse.
-l line
this info could go either way.
I elected to include it in LOOKUP, so in cache/inner fn.
this makes cache larger but avoids sprintf %d each time.
smaller cache needs smarter key.
All enabled together, they compose a prefix string like:
# outer -----inner----------------------
"[tid] module:function:sourcfile:line: "
So this patch extracts _DPRINTK_FLAGS_INCL_LOOKUP flags-combo out of
_DPRINTK_FLAGS_INCL_ANY, then redefs latter.
Next re-refactor dynamic_emit_prefix inner/outer fns accordingly.
Signed-off-by: Jim Cromie <jim.cro...@gmail.com>
---
include/linux/dynamic_debug.h | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 0f7476456614e..d64f13a7a7394 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -40,10 +40,11 @@ struct _ddebug {
#define _DPRINTK_FLAGS_INCL_SOURCENAME (1<<5)
#define _DPRINTK_FLAGS_PREFIX_CACHED (1<<7)
-#define _DPRINTK_FLAGS_INCL_ANY \
- (_DPRINTK_FLAGS_INCL_MODNAME | _DPRINTK_FLAGS_INCL_FUNCNAME |\
- _DPRINTK_FLAGS_INCL_LINENO | _DPRINTK_FLAGS_INCL_TID |\
- _DPRINTK_FLAGS_INCL_SOURCENAME)
+#define _DPRINTK_FLAGS_INCL_LOOKUP \
+ (_DPRINTK_FLAGS_INCL_MODNAME | _DPRINTK_FLAGS_INCL_FUNCNAME | \
+ _DPRINTK_FLAGS_INCL_SOURCENAME | _DPRINTK_FLAGS_INCL_LINENO)
+#define _DPRINTK_FLAGS_INCL_ANY
\
+ (_DPRINTK_FLAGS_INCL_TID | _DPRINTK_FLAGS_INCL_LOOKUP)
#if defined DEBUG
#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
--
2.50.1
